Wheel Bearing Torque Dos and Don'ts

Wheel Bearing Torque Dos and Don’ts

While it may appear to be easier to use an impact wrench, it is not recommended. OEM and bearing manufacturers always recommend using a torque wrench for installation. During removal, an impact wrench can damage the axle nut threads and shock the CV joints. It can also create a false sense of security when adjusting a nut or bolt, which may be under or over torqued.

Don’t Use an Impact For Installation or Removal
While it may appear to be easier to use an impact wrench, it is not recommended. OEM and bearing manufacturers always recommend using a torque wrench for installation. During removal, an impact wrench can damage the axle nut threads and shock the CV joints. It can also create a false sense of security when adjusting a nut or bolt, which may be under or over torqued. This can leave a hub assembly susceptible to failure. Also, in almost all cases, use a new axle nut. Some axle nuts are designed to be used only once, and can not be adjusted.

Do Check For the Recommended Torque Procedure
It is nearly impossible to give  a general torque specification for a locking nut. There can be large differences depending on bearing type and housing.  Always check the service information for the correct procedure. Overtightening adjustable tapered roller bearings is a common error that can lead to premature failure. Tapered roller bearings on the front of RWD vehicles are never preloaded. They’re snugged up with no more than 15 to 20 ft. lbs. of torque while rotating the wheel to make sure the bearings are seated. The adjustment nut is then loosened 1/6 to 1/4 turn, and locked in place with a new cotter pin. As a rule, endplay should be about 0.001 to 0.005 inches.

Many vehicles require the wheels to be on the ground for final torquing to OEM specifications. This assures the proper mating of the split inner rings of the bearing needed to achieve the proper internal clearance. For specific mounting instructions, refer to the vehicle manufacturer’s service manual for that model.

Don’t Reuse the Old Nut
Be aware that some hubs come with a new nut in the box. This is typically when a one-time-use, self-staking nut secures the hub. In these applications, a new nut must always be used when installing a hub. Reuse of the old nut could potentially cause the nut to loosen during vehicle operation.
Do Clean the Axle Shaft Before Installation
Clean and inspect the axle shaft prior to installing a new hub assembly. Use a fine file, wire brush, emery cloth or honing stone as appropriate to remove any debris, nicks or burrs. Don’t use any lubricants on the threads or washers. This can change the torque readings.

Do Not Forget to Inspect The Bore
Once the bearing is removed, inspect the bore of the knuckle for damage. The bore should be free from corrosion. Check the bore for roundness using a snap bore gauge. The gauge should rotate in the bore easily. Any distortion in the bore can cause a new bearing to fail ­prematurely.
Don’t Forget to Clean the Wheel Speed Sensor and Tone Ring
Cleaning the sensors and resetting the air gap can often restore normal operation. But if the tone ring is corroded or damaged, it must be replaced. Do this before the final torque is applied to the axle nut.
Do Measure Runout in the Flange After Installation
A distorted flange will have runout. This runout can cause vibration and eventually disc thickness variation in the brake rotors. Every manufacturer has its own specification for wheel flange runout. Most specifications fall between 0.0015” and 0”. Most manufacturers are moving to a zero runout and endplay specification in the flange. This “perfect” specification is  because any runout in the flange will be magnified by the rotor.
Don’t Use Your Torque  Wrench as a Socket Wrench
Use a torque wrench to apply a specific torque value during the final assembly process.  Do not use a torque wrench as the primary means of tightening or loosening fasteners.

You May Also Like

Auxiliary Water Pump Diagnostics

A car or truck comes into your shop with a complaint of poor heater performance. The driver complains that on cold mornings the heater will blow cold during the drive to work in rush hour traffic. The car is not overheating and the air is coming from the correct ducts. Your first reaction might be to install a new thermostat and inspect the heater core for a blockage. On the test drive, the system may perform great for you. Is the customer just cold blooded?

A car or truck comes into your shop with a complaint of poor heater performance. The driver complains that on cold mornings the heater will blow cold during the drive to work in rush hour traffic. The car is not overheating and the air is coming from the correct ducts.

VIDEO: Diagnosing The A/C Compressor Clutch

Andrew Markel discusses the clutch on the A/C compressor, and the signs to look for in your diagnostic to confirm its operation. Sponsored by Valeo.

Toyota FJ Cruiser Water Pump Replacement

Toyota’s original Land Cruiser was the company’s version of a Jeep that could go anywhere. In its time it was highly rated and collected, which led the Japanese juggernaut to bring back an updated SUV in 2007 called the FJ Cruiser. The retro-styled vehicle was again a go anywhere machine powered by a 4.0L V6 (1GR-FE) used in the Tacoma. The engines are durable and considered relatively robust for the time.

Long-Life Coolants Explained

Different types of coolants cover a range of applications from diesel to domestic, Asian and European vehicles. Each one is formulated to a specific manufacturer’s specifications to keep their engines at an optimal temperature. But, changes to the old one-size-fits-all formula has led to confusion for consumers and even some technicians.

VIDEO: Engine Efficiency Brings More Hoses

Andrew Markel discusses hoses and the necessity for several of them to route fluids to all parts of the vehicle due to the growing efficiency of engines. Sponsored by Dayco.

oil-coolant-hoses-video-featured

Other Posts

Wheel Bearings Components

Follow along to learn what you may encounter when dealing with a Gen 1 wheel bearing. This video is sponsored by The Group Training Academy.

Climate Control Modules

HVAC control modules may fail when the contacts and switches become inoperable. Sponsored by The Group Training Academy.

Why Does Engine Coolant Need Replacement?

Two specifications can be used to justify replacement — the condition of the additive package & the freezing point.

Tapered Wheel Bearings (VIDEO)

Tapered wheel bearings are still being used in certain applications. This video is sponsored by BCA Bearings by NTN.